Miniature electromagnetic relay

ABSTRACT

Electromagnetic relay comprising a fixed magnetic circuit and a movable armature for switching pairs of movable conductors. The movable conductors and the armature are installed inside the casing supporting the excitation winding at one end thereof and the release of the armature is provided by the spring portion of the movable conductors which are made in the shape of elastically flexible wires and are secured with this armature.

United States Patent Bloch 1451 Aug.`29, 1972 [541 MINIATURE ELECTROMAGNETIC [56] Roferenoes cited 72 ELAY P l Bl h S bo M UNrrED STATES PATENTS t t l 1 Ven or Frn ras rg emau 2,608,630 8/1952 Harrison ..335/135 x 2,662,135 12/1953 Seaton ..1.335/202 x [73] Assignee:` La Telephonie Industrielle et Com- 3,138,678 6/1964 Raab 335/203 x merelale Telle, Strasbourg- 3,333,216 7/1967 Stehlik -335/128 x Memau, France 3,544,930 12/1970 Sauer ..335/154 [22] Filed; Deo. 31, 1970 Primary Examiner-Roy N. Envall, Jr. [2l] Appl No-= 103,070` Anomey-cra1g,Antonoui & H111 [30] Foreign Aplillcation Priority Data n [57] ABSTRACT Deo. 31, 1969 France ..6945735 Electromagnetic relay compriSlng a fixed magnetic circuit and a movable armature for Switching pairs yof [521 U.S. c1. .;....335/151, 335/17, 335/128, movable conductora The movable conductors and thc x 33 5 /203 armature are installed insidethe casing supporting the [51] Int. C|..... .H01h 9/02, H0111 45/04, H0111 45/06 excitation winding at one end thereof and the release [58] mold ofsearoh ..335/17, 128,135,151,152, of the armature 1S provlded by the Spnng Portlon of 335/154, 202, 203; 337/241 the movable conductors which are made in the Shape of elastically flexible wires and are secured with this armature.

lClaimsADrwingFigures 13 3e; 8 3 r f, ""1 1I yIl 4 j *22 ^32 5L V 50 a a a a l een ff i' /`4 s l n f7, ^2s 12/ a k l14 2e 24 2 e Pfenged, Aug.' 29, 1912 3,688,229

2 'Sheete-Sheet 2 WNENTDRI PRUL. ESLUCH e, I Cm., nmmmmngmwmi' 9 www nrroRNeys The present invention relates to a miniature electromagnetic relay suitable for being mounted particularly on a map of printed circuits.

For this purpose, it is desirable to provide a relay which has small overall dimensions, is light and can be easily attached to or provided on a map of printed circuits either by plugging or soldering. It isl further required that a relay of this type be sturdy and very reliable, while having a low power consumption. Lastly, a

tion as well as simple regulation or control.

It is known that in a switch of the type of which the invention is directed, an R-T contact is provided which comprisesL a central element called a common contact and which, in the absence of excitation or energization of the relay, bears on a fixed so-called rest" contact. With the energization of the relay, due to the attraction of the magnetic circuit the common contactwill come to bear or act on another fixed contact, a socalled work contact.

The existing problem as stated above is solved, in accordance with the present invention, by providing a switch having a common contact consisting of a structure having an elongated shape, for example, a wire, rod or homogeneous resilient metallic bar. This common contact has a constant cross-section over the entire length thereof, comprising in an end region or area an anchored portion having an extremity serving as a connection on one side while the other extremity is divided successively into a first zone of elastic deformation, a second zone which is integral with a magnetic armature, a third zone also providing elastic deformation, and lastly, an extremity serving as the contact portion of the common contact. The aforementioned armature, which is made from soft magnetic metal, is connected with the structure of the common contact by means of an insulating body. The vane is placed opposite an opening in a C-shaped magnetic circuit which in operative connection with an excitation coil.

ln the non-energized condition, the contact portion of the elastic structure bears upon or is supported against the rest contact due to the e'ect of its elastic tension. When the coil is excited, the attraction of the vane by the magnetic circuit results in the shifting of the common contact to the working contact. When the current is suppressed in the coil, the elasticity of the structure resets or returns the common contact to the rest contact.

lt is an object of the present invention to provide a relay which eliminates or otherwise avoids the disadvantages inherent in known devices of a similar type.

It is another object of the present invention to provide a relay which is made up of a minimum number of elements.

It is a further object of the present -invention to provide a relay which is relatively simple to install and control in operation.

It is a further object of the present inventionto provide an electromagnetic relay having a magnetic circuit which need not have an annular configuration to properly operate the relay contacts.

It is still a further object of the present invention to provide a relay which is small in size and lightweight,

but sturdy and reliable in operation.

It is still another object of the present invention to provide a relay which has contacts of a noble metal, but is economical to manufacture.

These and other objects, features and advantages of the present invention will become more apparent from the following detailed description when taken vin conjunction with the accompanying drawings, wherein:

FIG. 1 illustrates schematically the basicelements of the present invention;

FIG. 2 is a side sectional view of one embodiment of the relay proposed by the present invention;-

FIG. 3 is a sectional view taken along line lI-II of FIG. 2; and

4 is an exploded perspective view of a portion of the disclosed relay.

As seen in FIG. l, a resilient elongated metallic structure A forms a common contact cross-section and the following operative zones: a, a first extremity serving as a connection portion for contact with an exterior circuit (not shown); b, an anchoring zone wherein the contact is supported by an insulating piece 28; c, a first zone of elastic deformation; d, a zone which is connected with a armature 18 made from soft magnetic material by means of an insulating body 20; e, a second zone of elastic deformation; and f, a second extremity serving as the contact portion of the common contact. The two fixed contacts have been designated, respectively, withreference symbols g (rest contact) and h (working contact).

The metallic vane 18 is placed adjacent the opening of a C-shaped magnetic circuit of which only the branches 14 and 16 have been shown in FIG. l. As is well known in the art, thebranches 14 and 18 close on a yoke and the magnetic circuit may be `subjected to the field of an induction coil (which have not been shown in FIG. l

In one embodiment of the present invention, illustrated in FIGS. 2 and 3, the relay is mounted in a casing 2, made for example,from hard plastic material, and comprising a tube 4 having a rectangular cross-section, having at the ends thereof flanges 6 and 8 being disposed at the respective ends thereof. Placed around the tube 4 between the flanges 6 and 8 is a winding 10 of an enameled copper wire for example.

A magnetic circuit comprises a yoke l2 forming a bridge between the edges of the flanges 6 and 8 on one side of the casing 2, a lower L-shaped branch 14 covering the portion of the flange 6 adjacent the yoke 12 and extending inside of the tube 4 through the bottom, an upper L-shaped branch 16 covering the portion of the flange 8 adjacent the yoke 12 and extending into the tube 4 from above. The yoke 12 engages in channels in the flanges 6 and 8, as is apparent from FIG. 3. For purposes of the installation, this magnetic circuit will consist of at least two parts which may be assembled, for

example, by gluing or any other simple equivalent fastening process. The magnetic circuit elements 12,` 14, and 16 consist advantageously of an alloy such as Anhyster or the like.

Adjacent the opening between the branches 14 and 16 of the magnetic circuit is a armature 18 made from a magnetic alloy which is connected, by means of a small insulating block 20, with a group of pairs of parallel wires 22 made of a resilient conductive alloy. A certain portion of these pairs of wires 22 is embedded or anchored in an insulating support 24 consisting, for example, of an organic polymer of the polyamide type or group, or the like. The insulating support 24 comprises an elongated block 26 which occupies the entire length of the tube 4 on the side opposite the magnetic circuit, and a short block 28 which serves to retain the lower branch 14 of the magnetic circuit and the pairs-of wires 22. These two blocks 26 and 28 may be interconnected by any known means, such as gluing, screwing, or merely the forcible engagement in the tube 4.

The tow parallel wires 22 of each pair constitute or make up the contact structure having the elongated form A as described in connection with FIG. l. The lower portion of the wires 22 passing or extending below the flange serves for the exterior connections to the relay, such as a sleeve (zone a in FIG. 1), and above this portion is the anchoring zone b. The central portion is connected with the magnetic annature 18 (zone d) by means ofthe insulting block 20. Situated between the block and the anchoring zone is the zone of elastic deformation c. Above the block 20 is a second zone of elastic deformation e, and the extreme end por tion of the wires 22 constitutes the contact portion of the common contact (zone f).

The fixed (rest-work) contacts are advantageously connected to or formed of two conductors 30 and 32 embedded in the body of the block 26 with the exclusion of the lower portion which passes below the flange 6 and of the upper portion which has a contact surface to the right of the upper end of the common contacts 22. It is particularly advantageous to employ as conductors 30 and 32 wires that are identical to the wires 22. In the preferred case, the upper end of the wires 30 and 32 is bent back first into the vertical plane and second into the horizontal plane, as is apparent from FIG. 2. The different rest-work contacts of the same relay are separated from each other by means of connecting pieces or sleeves, such as projections 34 in the block 26.

As seen in FIG. 2, at the upper portion of the relay is a lid 36 which is transparent and forms a magnifying glass. This lid is forcibly secured within the tube 4 by means of legs 38 and 40 shown in cross-section in FIG. 3. This lid may consist of methyl methacrylate or the like. The magnifying glass renders it possible to clearly see the contact zones of the fixed and movable conductors, whereby the good operation of the relay is assured.

It is preferable, but not essential, to use two wires 22 instead of a single wire in order to increase the reliability of the contacts, in accordance with current practice for relays specifically designed for the telephone industry.

The wires 22 are advantageously made of a eutectic alloy of silver and copper in a weight ratio of about work contacts, but it is understood that this number of I contacts has been indicated solely by way of example and is not intended to be limitative in any way. It is quite Y possible to either increase or decrease the number disclosed herein by increasing the size of the casing.

It should be noted that, in the relay proposed by the present invention, the magnetic' circuit does not require an opening, nor machining of any kind.

FIG. 4 shows an exploded view of the group of elements consisting of the common and fixed contacts of the relay according to the present invention. Also evident from this figure are the four pairs of wires 22 held in position by the block 20, which is made from insulating material and which is turn supports the magnetic armature 18.

The support 26 contains four pairs of wires 30 and 32 whose ends project or extend on one side from the support, the other ends of which are bent back twice in the manner already described. Projections 34 hold the upper ends of the wires 30-32 and separate the contacts of the relay from each other.

While I have shown and described one embodiment in accordance with the present invention, it is understood that the same is not limited thereto but is susceptible of numerous changes and modifications as known to a person skilled in the art, and I therefore do not wish to be limited to the details shown and described herein but intend to cover all such changes and modifications as are obvious to one of ordinary skill in the art.

What is claimed is:

1. A miniature electromagnetic relay comprising a plurality of fixed rest contacts andwork contacts, an elongated frame of insulating material having a rectangular cross-section on which there is wound at least one winding, a C-shaped magnetic circuit surrounding said winding on one side of said rectangular frame and having a gap disposed inside of said frame, at least one common elastically flexible wire contact having an elongated shape and constant cross-section, support means for supporting one end of said common contact in cantilever fashion inside said frame adjacent one end of said frame with said one end of said common contact extending out of said frame as a connection portion, a magnetic armature insulatingly secured solely to said common contact at a point substantially midway between said support means and the other free end of i said common contact inside said frame, said magnetic armature being disposed adjacent the gap in said magnetic circuit and the other free end of said common contact being disposed between at least one rest contact and one work contact.

2. A relay as defined in claim l, wherein said common contact is provided in the form of a pair of parallel wires.

3. A relay as defined in claim 2, wherein the wires forming said common contact are made from a silvercopper alloy in a weight ratio of about 72/28.

4. A relay as dened in claim 1, wherein said fixed rest contacts and said fixed work contacts each are formed by a wire extending substantially parallel to said common contact on the same side thereof and having a double bend at the end thereof adjacent the free end of said common contact inside said frame, while the other end thereof extends out of said frame to serve as a connection portion.

5. A relay as defined in claim 4, wherein said support l means includes an elongated insulating block disposed common contacts are supported by said support means within said frame.

7. A relay as dened in claim 6, wherein each of said common contacts is provided in the form of a pair of parallel wires.

8. A relay as defined in claim 7, wherein the wires forming said common contact are made from a silvercopper alloy in a weight ratio of about 72/28.

9. A relay as defined in claim 8, wherein said xed rest contacts and said fixed work contacts each are formed by a wire extending substantially parallel to said common contact on the same-side thereof and having a double bend at the end thereof adjacent the free end of said common contact inside said frame, while the other end thereof extends out of said frame 10. A relay as defined in claim 9, wherein a cover member is provided on the end of said frame opposite said support means in the form of a transparent magnifying glass. 

1. A miniature electromagnetic relay comprising a plurality of fixed rest contacts and work contacts, an elongated frame of insulating material having a rectangular cross-section on which there is wound at least one winding, a c-shaped magnetic circuit surrounding said winding on one side of said rectangular frame and having a gap disposed inside of said frame, at least one common elastically flexible wire contact having an elongated shape and constant cross-section, support means for supporting one end of said common contact in cantelever fashion inside said frame adjacent one end of said frame with said one end of said common contact extending out of said frame as a connection portion, a magnetic armature insulatingly secured solely to said common contact at a point substantially midway between said support means and the other free end of said common contact inside said frame, said magnetic armature being disposed adjacent the gap in said magnetic circuit and the other free end of said common contact being disposed between at least one rest contact and one work contact.
 2. A relay as defined in claim 1, wherein said common contact is provided in the form of a pair of parallel wires.
 3. A relay as defined in claim 2, wherein the wires forming said common contact are made from a silver-copper alloy in a weight ratio of about 72/28.
 4. A relay as defined in claim 1, wherein said fixed rest contacts and said fixed work contacts each are formed by a wire extending substantially parallel to said common contact on the same side thereof and having a double bend at the end thereof adjacent the free end of said common contact inside said frame, while the other end thereof extends out of said frame to serve as a connection portion.
 5. A relay as defined in claim 4, wherein said support means includes an elongated insulating block disposed inside said frame on the side thereof opposite said magnetic circuit and having said fixed rest and work contacts embedded therein, and another insulating block closing the end of said frame through which said common contact extends and supporting said common contact for movement within said frame.
 6. A relay as defined in claim 5, wherein a plurality of common contacts are supported by said support means within said frame.
 7. A relay as defined in claim 6, wherein each of said common contacts is provided in the form of a pair of parallel wires.
 8. A relay as defined in claim 7, wherein the wires forming said common contact are made from a silver-copper alloy in a weight ratio of about 72/28.
 9. A relay as defined in claim 8, wherein said fixed rest contacts and said fixed work contacts each are formed by a wire extending substantially parallel to said common contact on the same side thereof and having a double bend at the end thereof adjacent the free end of said common contact inside said frame, while the other end thereof extEnds out of said frame to serve as a connection portion.
 10. A relay as defined in claim 9, wherein a cover member is provided on the end of said frame opposite said support means in the form of a transparent magnifying glass. 